> > > SUPPORT CREATION WIKI < < <
Donate -or- Patronize our Creation Science Store

Carbon-14 dating

From CreationWiki, the encyclopedia of creation science

Jump to: navigation, search
Processing carbon samples for reading on a mass spectrometer to determine carbon isotopic composition.

Carbon-14 dating is a radiometric dating technique used to deduce the approximate age of organic remains by measuring the quantity of C-14 isotopes in the sample and comparing them with current atmospheric levels.

Contents

Methodology

C-12 and C-14 are two different isotopes of carbon. C-12 is stable, meaning it does not decay into other elements over time. However, C-14 is not stable. It is formed when cosmic radiation strikes N-14 (Nitrogen), converting it into C-14, and it decays back into N-14, with a half-life of 5730 years, meaning that for any sample of C-14, half of it will decay back into N-14 every 5730 years.

Carbon-14 is used to date dead plants and animals, because plants and animals incorporate C-14 into their bodies by eating, drinking, and breathing in an environment containing C-14. Through the life of the organism, the proportion of C-14 to C-12 reaches the same proportion as in the rest of the environment. When the organism dies, however, it ceases to incorporate carbon into its body. At this point, and for the years following, the C-14 in the sample begins to decay back into N-14, while the C-12 does not decay. Both C-14 and C-12 are lost as the body decays, but they are lost proportionally, so that the proportion of C-14 to C-12 decreases slowly for thousands of years after the death of the organism.

Today, scientists attempt to determine the age of dead organisms by measuring the ratio of C-12 to C-14, by comparing it to an assumed but unobserved initial ratio, and determining how long it would take to get from the assumed but unobserved initial ratio at an assumed but unobserved rate of decay.

Here are the key assumptions:

  • The C-14 to C-12 proportion was the same in the past as today. This assumption cannot be tested, because it is impossible to actually measure the proportion. However, there is solid evidence that the proportion of C-12 to C-14 was not the same in the past, but in fact was much lower.
  • The rate of decay from C-14 to N-14 has been constant since the organism died. This assumption also cannot be tested. Some creationists have asserted that there is evidence that the rate of decay has been slowly decreasing over time.

False assumptions

Constant C-14 to C-12 proportion

There is one fact that makes it highly unreasonable to believe that the proportion of C-14 to C-12 was the same in the past as it has been in recent history: It is not in equilibrium.

The rate of C-14 production today is 18% higher than the rate of decay (Whitelaw). This means that today we are experiencing a net increase in the proportion of C-14 in the atmosphere. It is impossible to determine whether it has always been increasing (as argued by some creationists) or whether it has undergone cycles of increase and decrease (as argued by other creationists and evolutionary scientists). But one thing is certain: there is no reason to believe that the C-14:C-12 proportion has been constant throughout time, and good reason to believe it has been different, and often lower, in the past than it is today.

If the C-14 content of the atmosphere was lower in the past, that means that Carbon dating results today are inflated, because the calculations will mistake the absence of C-14 in the original sample as years which passed by causing the C-14 to decay.

Recognizing this, many uniformitarian scientists calibrate their dating efforts to the early 19th century, in the belief that today's C-14 increase is due to the industrial revolution. This assumes, however, that today's C-14 increase is only the result of the industrial revolution (which is unfalsifiable) and that the proportion was in equilibrium prior to the 19th century (which is also unfalsifiable). In other words, while acknowledging the problem posed by the increasing C-14, the uniformitarian scientists have failed to solve it, and yet continue to use the methodology.

Pre-Flood Ratio Significantly Different

Carbon-14 dating is based on the ratio of available Carbon-14 versus what is actually found in living systems. If this ratio is inconsistent, Carbon-14 dating cannot be accurate.

If the fossil record is the record-of-death of the Great Flood, then the level of overall biomass prior to the Flood eclipses today's overall biomass by 100 times or more[1]. This would mean that, given a relatively constant C-14 production, the living systems prior to the Flood would have diluted the overall available C-14. This dilution artificially skews a measurement if we use today's ratios.

An example follows: We have a one-pint container and pour its contents into a graduated flask, then come back each day to check on the water's evaporation. Let's say that 1/4th of the water evaporates each day, so that at the end of day 3, someone notes that there is 1/4th of the water remaining, where 3/4ths have evaporated. Now take the same one-pint container and pour it evenly into four graduated flasks, each one initially containing 1/4th of a pint. Someone enters the room moments later and sees that a flask is only 1/4th full and presumes it has been there for three days. They are using the prior ratio, not the diluted one. This dilution effect would be so profound in the pre-Flood world that if we were to take a living organism and measure its Carbon-14 using today's ratio, it would appear to be many tens of thousands of years old.

This is a clear example of where uniformitarian assumptions break down because they presume that the processes and conditions in place today have been steady throughout time.

Evidence of Flood and Young Earth

While it can be shown that Carbon-14 dating should not be used to determine minimum ages for items, it may still be used to determine maximum ages, because Carbon-14 must decay at some point, and objects which contain C-14 in them cannot be older than their C-14 content would allow.

In fact, many objects which uniformitarianism would tag as millions of years old have been found with enough C-14 in them to require a much lower age.

  • Coal, natural gas, and even carbonate rocks all have enough C-14 to be dated to between 30,000 and 60,000 years..[1]
  • Unfossilized dinosaur bones date to between 10,000 and 50,000 years old.[2]
  • Carbonized wood is found in strata which is supposed to be hundreds of millions of years old.
  • CO2 from gas wells (obviously devoid of organic means to absorb C-14) contained C-14, indicating an age not to exceed 30,000 years.[3]
  • A 1978 UCLA study found C-14 in limestone.[4]

Given that the C-14 proportion is currently increasing, the actual age could in fact be much lower. But it cannot be higher, because if the coal and natural gas were as old as the evolutionary paradigm requires, the C-14 in them would have decayed long ago.[5]

Speculative uniformitarian explanations for the excess C-14

Evolutionists have speculated that the C-14 may be due to contamination from other radioactive elements in the surrounding rock. However, they have not backed these speculations with experiment or observation, which is, of course, the work of scientists.

Other evolutionists have speculated that the excess C-14 might be due to contamination in the sample. However, John Baumgardner, Andrew Snelling, Russell Humphreys, and Steven Austin, after noticing that C-14 abundances quoted in secular scientific journals consistently were higher than expected for certain organic materials, performed an experiment in which 10 pieces of coal were tested in a secular, high precision lab. These scientists had noticed that the distribution of abundances of C14 in substances derived from living animals (such as coal) was a different distribution from material that was from non-biological Precambrian specimens. This would suggest that the abundances being found by labs were not all due to a uniform contamination.

They report that the coal was measured as having an abundance well above the blank used by the laboratory representing unknown contamination. Their report can be found here.

Critics suggest that coal could have had carbon fixed by bacteria or fungus in the coal (Talk Origins). However, this does not explain the C-14 found in diamonds, or the source of C-14 in the coal layers for the bacteria/fungus to use, and creationists found that the labs themselves cannot explain the level of "contamination" that is found in the carbon they use for their "blanks."

There have also been more sensationalistic claims of C-14 anomalies in other materials, such as claims made that C-14 dating gave different dates for the inside and outside of a seashell, etc. Anti-creationists tend to have little problems finding explanations for these types of observations.

RATE Group's Research

C14c.gif

The RATE Group has found that Carbon 14 is found throughout the geologic column and the amounts do not vary with the location in the column above the Precambrian. This suggests that the layers formed quickly and at the about the same time. It further shows that the fossil organisms found in these rocks lived at the same time.

C14d.gif

The only trends are as follows:

  • In rocks alleged to be too old to have remaining C14
    • Dated < 600 Mya. average a C14 level of 0.292 pMC.
    • Dated > 600 Mya. average a C14 level of 0.062 pMC.
  • Recent objects show general lowering of C14 with age.

This is 100% consistent with a Young Earth creation model and the basic trend predicted by Young Earth creation.

Conclusion

Radiocarbon dating relies upon the assumption that C-14 production in the atmosphere has been constant during the history of life on earth. If the earth is billions of years old, then the rate of production and decay should have reached steady-state a long time ago. It is assumed that these rates should be at equilibrium, but today we know that the rate of C-14 production exceeds the rate of decay by as much as 25%. This increase is attributed to the recent industrial revolution, and believed to be primarily due to atmospheric nuclear testing. However, it is assumed that before the industrial revolution, the rates should have been at steady-state. Therefore to correct for the increased rate of C-14 production, a sample is used from early in the 19th century as a standardizing reference.

If the rate of C-14 production in the atmosphere was less in the past than it is today, then samples would seem excessively old. From Biblical references and modern data there is good evidence that our atmosphere has changed dramatically. It can be inferred from the Bible text that there was no rainbow before the flood, which must mean the atmosphere was altered significantly by the flood. We also know the atmosphere continues to change. Today we have evidence of global warming, and holes in the ozone layer; indicating a change in both composition and partial pressure of the atmosphere that could cause higher rates of C-14 production. Variations of the earth's magnetic field may also be a factor affecting the flux of cosmic rays by altering the degree of shielding. Belief in an old earth has led to assumptions that C-14 production and decay should be at steady-state. Radiocarbon is therefore being used for dating when we simply have no way to determine what the rates of C-14 production were in the past. One thing we do know for sure, is that C-14 is being produced at higher rate today, and it is assumed that this increase began only recently.

Quote from The Great Dinosaur Mistake by Kelly L. Segraves:

...carbon 14 has problems. It is based upon the assumption that the rate of the formation of carbon 14 in the upper atmosphere is equal to the rate of decay. This is not true. Dr. Libby, who invented the method, says it must be true because it would only take 30,000 years for equilibrium to be established, for the rate of formation to be equal to the rate of decay. He says everyone knows that the earth is over 30,000 years old so carbon 14 must be in equilibrium. Yet the latest studies indicate the rate of formation is not equal to the rate of decay. If allowance is made for Libby's erroneous assumption, the corrected carbon 14 dates come back to within the last 5000 years. But even then there are still problems. Carbon 14 analysis, as in the case of other dating methods, does not really determine anything about age; it simply tells you the amount of carbon 14 found in a substance. Carbon 14, formed in the upper atmosphere, filters down into the plants, and one eats either plants or things that have eaten plants. Therefore, a certain amount of carbon 14 is trapped in your body and bones. Scientists measure how much is present and, based on the half life of carbon 14, they project back in time to see how long you must have been around. Theoretically, that is how ages are determined by carbon 14. But there are some problems again, because penguins living in the Antarctic today have yielded 3000 year old carbon 14 ages when tested. Seals killed recently gave ages of 1000 years...

References

Creationist

Secular

Related links

Creationwiki chemistry portal.png
Browse


See Also


Cite error: <ref> tags exist, but no <references/> tag was found
Personal tools